This example demonstrates how to do a node-based comparison of species distributions, as described in Borregaard, M.K., Rahbek, C., Fjeldså, J., Parra, J.L., Whittaker, R.J. and Graham, C.H. (2014). Node-based analysis of species distributions. Methods in Ecology and Evolution 5: 1225-1235. It demonstrates the whole process of loading the data and developing the method, as a case study example.

Load data and create objects

First, let's load the data. We have the data in two DataFrames, one of species occurrences in each grid cell, and one with the lat-long coordinates of each grid cell. The DataFrame of occurrences is in the widely used phylocom format, which is a long-form format for associating the occurrence of species in sites. It consists of three columns, a column of species names, one of abundances (here 1, as it's a presence-absence data set) and a column of sites.

using CSV, DataFrames, SpatialEcology
phylocom = CSV.read("../../data/tyrann_phylocom.tsv", DataFrame)